1. Field of the Invention
The present invention relates to a door construction for a vehicle provided with double doors that open outward to form a single uninterrupted doorway to front and rear seats which ensures strength of a side body against lateral external impact even though having no center pillars.
2. Description of Related Art
Motor vehicles with double doors, typically such as front and rear doors opening outward, provide a single doorway to front and rear seats when the double doors open. Such a motor vehicle has no center pillars and, in consequence, has need to be equipped with improved rigidity of a doorway structure and strength and rigidity of door units. As described in, for example, Japanese Unexamined Patent Publication No. 10-250370, one of general measures for improving strength and rigidity of a door unit is to provide the door unit with an impact load carrying bar extending in a lengthwise direction in an inside space of the door unit so as thereby to ensure strength of the side body against lateral external impact.
In addition, the motor vehicle having no center pillars is hard to ensure mounting rigidity of a functional member such as a seatbelt retractor. In order to eliminate this problem, it has been proposed in, for example, Japanese Unexamined Patent Publication No. 2001-138864 to mount upper and lower door locks to upper and lower front portions of a rear door, respectively, by the use of upper and lower mounting brackets, respectively. The upper mounting bracket is commonly used to mount a shoulder belt anchor of a front seat belt to the vehicle, and the lower mounting bracket is commonly used to mount both lap belt anchor and seat belt retractor of the front seat belt.
It is therefore an object of the present invention to provide a double door construction for a vehicle having no center pillars that ensures strength of a side body of the vehicle.
It is another object of the present invention to provide a double door construction for a vehicle having no center pillars that has no need to install additional reinforcing members for mounting functional devices or members such as a retractor of a seat belt to a door.
The aforesaid objects of the present invention is accomplished by a double door construction for a vehicle having front and rear doors opening outward to provide a single uninterrupted opening which comprises vertical impact load carrying means installed to at least one of the front door and the rear door and extending substantially vertically along an end of the door opposite to an end at which the door is pivotally mounted to a vehicle body.
The impact load carrying means at either one or both of upper and lower end portions desirably overlaps a rigid stationary portion forming side part of a vehicle body. The double door construction thus constructed cooperates with a side body of the vehicle thereby to provide improved side body strength against lateral impact upon an occurrence of a lateral collision of the vehicle.
Specifically, the impact load carrying means desirably comprises an impact bar and a bracket fixedly attached to each of the upper and lower end portions of the impact bar through which the impact bar is rigidly fixed to the door. The bracket can be used to mount a functional member or members of a mechanism or a system operative to protect passengers, such as a door latch of a door lock mechanism, catch pins of a door catch mechanism operative to prevent movement of the door upon an occurrence of a side collision, or a belt anchor of a seatbelt system, without installing extra reinforcements for mounting these functional members.
The door and the reinforcement are desirably made of aluminum. On the other hand, the impact load carrying means is desirably made of iron metal and, more specifically, comprises an impact bar made of high-strength steel and brackets made of iron. When the double door is constructed by the use of structural members made of different materials, the door to which the impact load carrying means is installed is provided with an aluminum reinforcement extending along with the impact load carrying means and coupling means for mechanically coupling the impact load carrying means and the reinforcement together so as thereby to absorb relative displacement between the impact load carrying means and the reinforcement due to differences in thermal expansion of them during manufacturing process, e.g. a painting and drying process, of the door.